Trimmer capacitor

ABSTRACT

A variable electronic component having a plurality of unmounted coacting elements adaptable in particular for attachment in subminiature electronic circuits on a supporting substrate includes, at least one conductive contact means connected to one side of the circuit and adjustable means independent of and in spaced relation to said contact means for operative coaction therewith. The adjustable means has at least one support member of conductive material connected to the other side of the circuit and at least one movable means in current conducting relation with and slidably or rotatably disposed on the support member for guided movement into and out of engagement with the contact means. Means are provided to maintain the movable means in adjusted position of engagement with the contact means, and means disposed between the contact means and the movable means is provided to establish a desired impedance characteristic for said electronic component.

United States Patent Newman et a1. July 25, 1972 54] TRIMMER CAPACITOR865,462 4/1961 Great Britain .317/249 "r [72] Inventors: Richard J.Newman, West Orange; Martin A. Mittler, Parsippany; Martin J. PrimaryExaminer-E. A. Goldberg Bllckstein, West Caldwell, all of NJ. A l0rnevPopper, Bain, Bobis & Gilfillan [73] Assignee: Voltronics Corporation,Hanover, NJ.

[57] ABSTRACT [22] Filed: Jan. 21, 1971 [21] APPLNO: 108,294 A variableelectronic component having a plurality of unmounted coacting elementsadaptable in particular for attachment in sub-miniature electroniccircuits on a supporting [52] U.S. CI. ..317/101 C, 317/249 T, 317/251substrate includes, at least one conductive contact means con- [51] Int.Cl. ..I-I0lg 5/14 nected to one side of the circuit and adjustable meansinde- [58] Field of Search ..3l7/249 R, 249 T, 251, 101 C, pendent ofand in spaced relation to said contact means for 317/l01CC operativecoaction therewith. The adjustable means has at least one support memberof conductive material connected References Cited to the other side ofthe circuit and at least one movable means in current conductingrelation with and slidably or rotatably UNITED STATES PATENTS disposedon the support member for guided movement into 1,548,801 8/1925Jacobs..; ..317/251 n out f ng g m wi h h Contact me M n are 1,567,06812/1925 Lindberg 317/251 provided to maintain the movable means inadjusted position 1,641,635 9/1927 Klein ....317/249 R of engagementwith the contact means, and means disposed 2,751,444 6/1956 Koch....317/249 R between the contact means and the movable means is pro-2,849,666 8/ 1958 Seageant ....317/249 R vided to establish a desiredimpedance characteristic for said 3,034,027 5/1962 Swick ..317/249 Telectronic component.

FOREIGN PATENTS OR APPLICATIONS 20 Claims, 24 Drawing Figures 382,54510/1932 Great Britain ..3l7/249 DIELECTRI C MATERIAL PAIENTEDJuL 25 I972SHEEI 1 OF 5 DIELECTRIC MATERIAL] RICHARD J NEWMAN MARTIN A.M|TT1' ERMARTIN J,BLICKSTE1N I INVENTOR.

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D J R N MTT C |AHA RMM TRIMMER CAPACITOR BACKGROUND OF THE INVENTION Inthe advancing technologies of computers, testing equipment, appliancesand other fields various types of hybrid electronic circuits, integratedelectronic circuits, micro strip amplifiers, micro electronic systemsand other electronic devices are being developed which are made onincreasingly smaller scales and sizes than has been known theretofore.

In accomplishing this end, the enumerated devices and systems aregenerally mounted on small flat insulating bases known as substrates andthese various systems or devices incorporate or have formed therein orcoact with various types of electronic components such as inductors,capacitors, resistors, potentiometers, etc., which in turn must be assmall as possible to meet the demands of the reduced scale or size ofthese systems and devices.

The known prior art miniature components have about reached theirfunctional limit even with the best precision manufacturing techniquesbecause certain elements of such devices cannot be reduced further atreasonable costs for commercially acceptable regularlyusable components.

For example, the present known prior art variable trimmer capacitorsheretofore used in miniature electronic circuits require a mountingframe and a tuning mechanism and there is a limit as to how theseelements can be miniaturized and still provide effective and properfunction.

Further, the mounting elements and tuning mechanisms, when connected inminiature electronic circuit handling high frequencies create unwantedinductance and capacitance in the systems and devices in which they areused because they form stray current paths when placed in closeproximity to each other; as may be required in miniature systems orsmall electronic designs; they produce unwanted circuit interaction suchas excessive coupling.

The present invention provides a variable electronic component which isparticularly adapted to meet and overcome the problems of these priorart devices and accomplishes this by eliminating the area and mass ofconventional mounting frames, tuning mechanisms and other elementsheretofore used; and instead integrates the elements of the variableelectronic component into the circuit.

The present device is primarily designed as a low profile structureexceedingly small in size, simple in construction, easily adjustable,reliable in operation, easily replaceable and reproducible in quantitywithout sacrificing uniformity of performance.

SUMMARY OF THE INVENTION Thus, the present invention covers a variableelectronic component having a plurality of unmounted coacting elementsadaptable for use in sub-miniature electronic circuits on a supportingsubstrate which comprises, a conductive contact means connected to oneside of said circuit, a support member or holder of conductive materialindependent of said contact means connected to the other side of saidcircuit and disposed in predetermined spaced relation to said conductivemeans, means movably mounted in said support member or holder andadjustable for guided movement into and out of engagement with saidcontact means, means to hold said movable means in any given adjustedposition of engagement or nonengagement with said contact means, andmeans between said conductive and said movable means to provide adesired range of impedance characteristics to said electronic component.

OBJECTS AND ADVANTAGES Accordingly, it is the primary object of thepresent invention to produce a variable electrical component in whichthe part or parts thereof are independently mountable in currentconducting circuit disposed on an associate substrate.

It is another object of the present invention to provide a variableelectronic component which is relatively small and cheap to buildwherein the area and mass of conventional mounting means and tuningmeans of the known prior art devices are substantially eliminated.

It is another object of the present invention to provide a variableelectronic component particularly adapted for use in high frequencysub-miniature electronic systems and devices.

It is another object of the present invention to provide a variableelectronic component which is relatively easy to adjust to provide finetuning for the electronic circuit in which it will be used.

With the above considerations and objects in mind, the invention itselfwill now be described in connection with several preferred embodimentsthereof given by way of example and not by way of limitation and withreference to the accompanying drawings in which:

FIG. I is a highly enlarged plan view of a micro-lumped thin filmcircuit having a variable trimmer capacitor thereon in accordance withthe present invention.

FIG. 2 is an enlarged exploded view of the variable trimmer capacitorshown in FIG. 1.

FIG. 3 is an enlarged side elevational view of the variable trimmercapacitor shown in FIG. 1 in assembled relation showing a fragmentaryportion of the circuit and the substrate on which the trimmer ismounted.

FIG. 4 is a top plan view of the assembled variable trimmer capacitorshown in FIG. 3.

FIG. 5 is a vertical section taken along line 55 of FIG. I illustratingthe movable member phantomized in various positions of engagement withthe contact means.

FIG. 6 is a view from the right end of the variable trimmer capacitorshown in FIG. 3.

FIG. 7 is a vertical section taken along line 77 of the variable trimmercapacitor shown in FIG. 3.

FIG. 8 is a vertical section taken along line 8-8 of the variabletrimmer capacitor shown in FIG. 3.

FIG. 9 is an enlarged exploded view of another form of variable trimmercapacitor in accordance with the invention.

FIG. 10 is an enlarged side elevational view of the form of variabletrimmer capacitor shown in FIG. 9 in assembled relation with the movablemember or shuttle phantomized in various positions of engagement withthe contact means.

FIG. 11 is a top plan view of the assembled variable trimmer capacitorshown in FIG. 10.

FIG. 12 is a vertical section taken on line I2-l2 of FIG. II.

FIG. 13 is a vertical section taken on line 13-13 of FIG. 10.

FIG. 14 is a right end view of the variable trimmer capacitor supportshown in FIG. 10.

FIG. 15 is an enlarged perspective view of another form of contact meansfor the form of the invention shown in FIGS. 3-9 of the drawings.

FIG. 16 is a side view of the contact means shown in FIG. 15.

FIG. 17 is an end view of the end of the contact means shown in FIG. 15which faces and is engaged by the movable member of the variable trimmercapacitor shown in FIGS. 38 of the drawings.

FIG. 18 shows a movable member in engagement with the contact meansshown in FIG. 16 in various positions as shown by the solid and thedotted lines.

FIG. 19 is an enlarged exploded view of a variable resistor inaccordance with the present invention.

FIG. 20 is an enlarged side elevational view of an assembled variableresistor as shown in FIG. 19.

FIG. 21 is a top plan view of the assembled variable resistor shown inFIG. 20.

FIG. 22 is a vertical section taken on line 22-22 of the assembledvariable resistor shown in FIG. 21.

FIG. 23 is an end view taken from the left-hand side of the variableresistor shown in FIG. 20.

FIG. 24 has elements similar to the device shown in FIGS. 19 to 24 butshows an enlarged exploded view of the movable member modified toprovide a variable trimmer capacitor having a chip from the circuitconverted into an element of the trimmer capacitor.

ONE FORM OF VARIABLE TRIMMER CAPACITOR Referring to the drawings, FIG.illustrates a variable trimmer capacitor generally designated 20 inaccordance with the present invention applied to a subminiatureelectronic circuit of the micro-lumped thin film construction generallydesignated 10 which is used for example in 2 01-12 5 watt poweramplifier. The electronic circuit is illustrated in highly enlarged formas its actual dimensions are about one square inch. v

The variable trimmer capacitor 20 illustrated will have actualapproximate dimensions and sizes as follows Height 0.04 inch, Width 0.07inch and Length 0.200 inch. A variable trimmer capacitor with thesedimensions will have a capacitance range from 0.1 pf to above 2.5 pf(pico farads); minimum voltage ratings will be 100 volts DC and a Q over1,000 at 100 GHZ.

It is noted that in all the other forms of the present inventionillustrated in the various figures to be described hereinafter that theelements are also shown in highly enlarged form to more clearlyillustrate the construction and arrangement of the parts. It will beunderstood that these forms of the invention may also have dimensionssimilar to those above indicated for the variable trimmer capacitorillustrated in FIGS. 3 to 8 of the drawings. 2

The micro-lumped thin film construction shown in FIGS. 1 and 2 comprisesa substantially planar member having an alumina substrate generallydesignated A which is metalized and etched on at least one side to formcurrent carrying sections as at 13 and strips 14 to provide anelectronic circuit.

One of the current carrying section 13 is maintained intact as theground plane and the current carrying strip 14 and other strips inspaced relation to provide a plurality of patterns which form thefunctional components of the circuit indicated by the letters C" forcapacitors and L for inductors. Such forms of circuitry are well knownin the'prior art and must be made with great precision. FIGS. 1 and '2further show that the variable trimmer capacitor includes a conductivecontact means 21 connected to the current carrying strip 14 of theelectronic circuit disposed on the substrate A and spaced therefrom is asupport member or shuttle holder 22 also made of conductive material andconnected to the side of the circuit elements 13 forming the groundplane GND opposite in the circuit from that to which the conductivecontact means 21 is connected.

The support member is so spaced that a movable member or shuttle 23mounted on the support member 22 can be moved into and out of engagementwith the contact means or clasp v 21. The coaction between the movablemember and the contact means will perform the operative function of thevariable trimmer capacitor as is explained more fully hereinafter.

The variable trimmer capacitor is affixed in properly adiusted positionfor the desired interrelation between the movable member or shuttle 23and the contact means or clasp 21 as by solder means 24 for affixing theelements to the electronic circuit parts. Alternatively the elements ofthe variable trimmer capacitor can be affixed directly to the substrateand connected by suitable lead lines, not shown, to the currentconducting section 13 and the current conducting strip 14 of theelectronic circuit formed on the substrate A. Thus, there is noindependent mounting frame or other means provided for the elements 21,22 and 23 of the variable trimmer capacitor. The elements 21, 22 and 23are integrated directly into the electronic circuit as a componentthereof. I

The contact means or clasp 21 and the support member or shuttle holder22 may be made of substantially similar materials. One such materialparticularly adapted for this purpose is a beryllium copper alloy. Thismaterial is desirable for this purpose in that it is a fine grainedmetals which conducts current well. It can be easily shaped, can behardened into and will retain a shape or configuration such as theU-shape or bobby-pin shape of the respective contact means or clasp 21and the support member 22 as shown in side elevation in FIGS. 3 and 5 ofthe drawings. Alternatively other materials such asnickel-chromium-steel alloys or phosphor bronze alloys may be used.

Additionally. the contact means or clasp 21 and support member 22 can begold plated or silver plated by any suitable means because this willmake the elements non-corrodable, give them high electrical conductivityand facilitate soldering them to the electronic circuit in whichthevariable trimmer capacitor will be used.

The movable member or shuttle 23 is preferably made of stainless steelalloy 304. This is a nickel-chromium alloy which is commerciallyavailable on the open market. It is spring-like, noncorrodable andnon-solderable by the conventional techniques applicable to the contactmeans 21 and the support member or shuttle holder 22. Thus, when thevariable trimmer capacitor is affixed in assembled position in theelectronic circuit the movable member a shuttle 23 will not be affectedby the soldering action required for such assembly.

It is thought clear from FIGS. 1 to 8 that the elements of the variabletrimmer capacitor are shown to have no independent mounting means andthat the elements are independently and directly connected into thecircuit itself hence they are supported by the same substrate thatsupports the circuit. The only requirement to get effective operation isto so space the contact means 21 and the shuttle holder 22 that themovable member or shuttle 23 can be brought into and out of fullengagement with the contact means or clasp 21 as is shown by thephantornized lines in FIG. 5 of the drawings. This is best understood bynow describing the construction of the support member or shuttle holder22 and the movable member or shuttle 23 mounted therein and theirrelation to the contact means 21. I

Thus, referring to FIGS. 3 to 8 of the drawings, the support member orshuttle holders 22 is shown to be substantially U- shaped or bobby pinshaped in side elevation. It can be stamped, formed or shaped from arelatively thin flat member of conductive material such as berylliumcopper alloy for the reasons above set forth.

The support member 22 has an upper leg 25 and a horizontal lower leg 26,and continuous with one end of the legs 25 and 26 is a rounded base orconnecting section 30. The lower face of the lower leg 26 is soldered tothe current conducting section 13 as at 27. The free ends 28 and 29respectively of the upper leg 25 and lower leg 26 are closer togetherthan the portions of the respective legs remote from the free ends whichare continuous with the rounded connecting section 30. The upper leg 25is thus in compression or stress with respect to the lower leg 26 andthe arrangement forms a wedge shaped space 31 wherein the upper surface32 of the lower leg 26 provides a horizontal or flat planar engagingsurface.

Additionally the upper leg 25 is provided with a pair of shuttle guides33 and 34 which are connected on opposite side normal to the upper leg25 as shown in FIGS. 3, 4 and 5 of the drawings. The shuttle guides actfundamentally to prevent sidewise movement or slippage of the shuttle 23during movement or when it is in adjusted position.

The movable member or shuttle 23 is also a substantially U- shapedmember having an offset upper leg 40 and a horizontal lower leg 41. Theupper leg 40 will be disposed at substantially the same angle as theupper leg 25 of the shuttle holder 22 and will at the free end thereofhave an upturned gripping tab or element 42. The upper leg 40 and lowerleg 41 are connected by the rounded base on connecting portion 43.

The horizontal lower leg 41 has a contact shoe or arcuate section 44formed adjacent the free end of the lower leg.

To provide the desired function as a capacitor in the circuit the entireouter face 45 Le, the surface facing and to be brought into engagementwith the contact means 21 will be coated to the desired thickness with asuitable dielectric material such as polytetrafluoroethylene. It will beunderstood that other dielectric materials such as the ceramic coatingspresently in use on piston type variable trimmer capacitors could alsobe applied to the outer surface of the shuttle to accomplish the sameresult.

Alternatively, the inner surface of the contact means 21 could be coatedwith such dielectric material or other techniques could be used toestablish the desired capacitance without departing from the spirit orscope of this invention.

The movable member or shuttle 23 will be assembled to the support memberor shuttle holder 22 by passing the horizontal lower leg 41 of theshuttle 23 into the wedge shaped space 31 between the upper leg 25 andhorizontal lower leg 26 of the shuttle holder 23 as by springing theupper leg 25 away from the lower leg 26. The free end 28 of the upperleg 25 will return to its normally stressed position and bring the faceof the horizontal leg 41 of the shuttle 23 into initimate engagementwith the upper face or surface 32 of the horizontal lower leg 26 of theshuttle holder 22. At the same time this will act to bring the contactshoe or arcuate section 44 of the lower leg 41 into engagement with theunderside or lower face of the upper leg 25 of the shuttle holder 22.

Since the movable member or shuttle 23 can be suitably sized, the widththereof can be adjusted to permit the shuttle 23 in assembled positionto be in frictional engagement with the inner faces of the shuttleguides 33 and 34, as is shown in FIGS. 3 and 4 of the drawings.

The contact means 21 is made of a relatively thin, flat, conductivemember which may be formed, stamped or bent into a U-shape. Thus thecontact means 21 will also have an upper leg 51 and a horizontal lowerleg 52. The lower leg 52 is connected to current conducting strip 14 ofthe electronic circuit by solder 24 or other suitable means. Inassembled position the horizontal lower leg 52 provides a substantiallyflat planar inner surface 54. The upper leg 51 is spaced from the lowerleg 52 by the rounded end section 55 which connects leg members 51 and52 to each other.

By reference to FIGS. 3, 4 and 5 when the movable member 23 is not inengagement with the contact means 21 the free end 56 of the upper leg 51will be disposed closer to the free end 57 of the lower leg 52 toprovide a wedge shaped space 58 therebetween. In other words, the upperleg 51 will be prestressed or in compression relative the lower leg 52.As a result, when the movable member 23 is forced into engagement withthe inner surface of the contact means 21 the movable member 23 will beheld in firm engagement with the inner surface 53 and flat planarsurface 54 of the contact means 21.

The free end of the upper leg 51 is turned or bent slightly outward asat 59 to provide an abutting surface which will initially guide therounded connecting end 43 of the movable member or shuttle 23 as thismember is moved into engagement with the contact means.

The compressive forces and frictional engagement between the shuttleholder 22 and the shuttle or movable member 23 and between the movablemember 23 and the contact means or clasp 21 will act to keep therespective adjacent and contacting surfaces of the movable member 23,the inner surface 32 of the support member and the inner surface 54 ofthe contact means in close and intimate engagement. This will insureboth proper electrical contact and proper function of the variabletrimmer capacitor.

FIGS. 3, 4 and 5 further show that by acting on the upstanding grippingtab 42 as with any suitable adjusting tool for example, a tweezer, themovable member or shuttle 23 can be moved forward and back between aminimum and a maximum position. The minimum position is identified atFIG. 3 where the contact shoe or arcuate section 44 at the free end ofthe lower leg 41 is in engagement with the rounded connecting section30. This is the minimum capacitance position for the capacitance rangeof this form of the invention.

As is illustrated in FIG. 5, by the phantomized lines the shuttle 23 canbe moved to various positions of engagement with the contact means 21and the maximum capacitance position for the capacitance range of thisform of the invention is illustrated by the engagement of the roundedconnecting section 43 of the shuttle 23 with the inner surface of therounded connecting section 55 of the contact means 21.

This construction makes is impossible to overdrive the respective partsof the disclosed variable trimmer capacitor 20 shown in FIGS. 3 to 8 andthe shuttle guides 33 and 34 will prevent sidewise movement.Accordingly, disassembly of the elements of the variable trimmercapacitor 20 cannot occur in the form of the invention shown in FIGS. 3to 8 of the drawings above described.

The prestressed condition of the contact means 21 will act to force therespective outside or coated face 45 of the movable member or shuttle 23into intimate engagement with the innerface 53 of the contact means orclasp 21 and since the respective members 21 and 23 are conductive andare separated by a dielectric they form a relative simple adjustablecapacitor.

Additionally, the compressive forces and the frictional engagementbetween the elements of the variable trimmer capacitor 20 abovedescribed will normally be sufficient to maintain the shuttle ormovablemember 23 in any given adjusted position because the mass of theshuttle 23 is so small that it has little tendency to shift position. Itis however relatively simple to provide positive means to prevent suchmovement as by cars, not shown, which may be struck inwardly on theshuttle guides 33 and 34 or detent means not shown can be provided tocoact with the movable member or shuttle 23 as will be understood bythose skilled in the electro-mechanical arts.

ANOTHER FORM OF VARIABLE TRIMMER CAPACITOR FIGS. 9 to 14 show anotherform of variable trimmer capacitor in accordance with the presentinvention in which the fundamental elements perform the same functionsin substantially the same way.

In enlarged perspective form therefor FIG. 9 shows a variable trimmercapacitor generally designated 60 having a contact means or clasp 61, asupport member or shuttle holder 62, and a movable member or shuttle 63.

The contact means or clasp 61 and the shuttle holder 62 are made ofconductive materials and are substantially U-shaped inside view as isclear from FIGS. 10, 11, and 13. The materials used are thin, flatmembers of beryllium copper, nickelchrome steel alloy and phosphorbronze and are gold or silver plated as above mentioned for the variabletrimmer capacitor shown in FIGS. 3 to 8. They are made by shaping,forming or stamping those or any other materials which are conductiveand can hold the desired engagement with the movable member or shuttle63.

The contact means or clasp 61 includes a horizontal lower leg 64 and anupper leg 65 which are connected at one respec' tive end by a roundedend section 66 so constructed that the legs 64 and 65 respectively actas resilient or spring like members. The upper leg 65 has a groove 65astruck along the axial or longitudinal line which extends to and flareslightly as at 65b at the free end of the upper leg 65. The free end isbent outwardly or upwardly as at 68. This will open the space betweenthe adjacent free ends of the respective lower leg 64 and upper leg 65to facilitate entry of the end of the movable member or shuttle 63 intothe contact means or clasp 61 as is hereinafter described.

The contact means or clasp 61 will be afiixed to the electronic circuitas by solder or other suitable technique in the same manner abovedescribed for the contact means 21 of the form of this invention shownIn FIGS. 3 to 8 of the drawings.

Since this form of the invention is to act as a capacitor it isnecessary to provide a suitable dielectric between the coacting plates.For this purpose the entire inner surface of the contact means or clasp61 will be coated as at 68 with polytetfluoroethylene or a suitabledielectric. Thus when the shuttle 63 is moved into engagement with theclasp 61, the conductive portion of the clasp 61 acts as one plate andthe shuttle 63 as the other, the dielectric coating 68 being disposedbetween these plates in the required manner to provide the desiredcapacitance.

The support member or shuttle holder 62 a1so includes a horizontal lowerleg 70 which provides means to permit the shuttle holder 62 to beconnected into the circuit as was above described for the shuttle holder22 of the form of the invention shown in FIGS. 3 to 8 of the drawings.

Coacting with the horizontal lower leg 70 are a pair of upper legs 71and 72 which are connected in spaced relationship to a rounded endsection 73 to provide a longitudinal channel guide 74 therebetween. Therounded end section 73 is so formed that the upper legs 71 and 72 actasresilient or spring elements or leafs with respect to the lower leg 70.

At the free end remote from the end connected to the rounded end section73 the legs 71 and 72 have adjusting tabs 75 and 76 which provide meansfor engagement by a suitable tool not shown for adjusting this form ofvariable trimmer capacitor. i

The movable member or shuttle 63 which coacts with the shuttle holderfor this form of the invention is a flat member having an upstandingguiding tab 77 and one end which may be used above or in associationwith adjusting tabs 75 and 76 to move the shuttle 63 so as to adjust itslongitudinal position with respect to the contact means or clasp 61.

The guiding tab 77 will be sized so that the width thereof will permitit to fit snugly in the guiding channel 74. I e

In alignment with the guiding tab 77 is a center guide 78 which may beformed on the shuttle 63 by any suitable means such as by striking thesame from the under-surface of this member.

The center guide 78 will engage the centrally extending groove 65a inthe contact means or clasp 61 when the movable member or shuttle 63 ismoved to engage said clasp 61, as is illustrated in FlG. 10 and willprevent lateral movement of the shuttle during adjustment or when theshuttle 63 is in either assembled position, or adjusted position. i

The elements are assembled or connected to the circuit inpredeterminedspace relation to each other, as a function of the lengthofthe shuttle 63 such that when the shuttle 63 is in the maximumcapacitance position of engagement that is with its forward edge inabutment with the coated inner wall of the rounded end section 66 of theclasp 61 a sufficient length of the shuttle 63 will still remain in theshuttle holder ,62 so that the guiding tab 77 will still beengaged inthe guiding channel FIG. 11 shows that the movable member or shuttle 63may be moved to a minimum capacitance position that is when the shuttle63 is not in engagement with the stator clasp 61 and the back endthereof is in abutment with the inner wall of the rounded end section 73of the shuttle holder 62.

Those skilled in the art will recognize that each variable trimmercapacitor in accordance with the present invention will have-a range ofcapacitance as a function of the area of the plates and the thickness ofthe dielectric, and that the capacitance can be infinitely varied withinthe minimum and maximum limits of that range.

Rough tuning of the electronic circuit in which the trimmer capacitor ismounted can be accomplished by manual movement of the movable members orshuttles 23 or 63 respectively. Fine tuning of the electronic circuit ismore easily accomplished by using an adjusting tool in association withsuitable test instruments, also not shown, to move the movable mem bersor shuttles 23 or 63 respectively in incremental steps until optimumoperating conditions are obtained.

ALTERNATE FORM OF CONTACT MEANS OR CLASP FIGS. 15. 16 and 17 show analternate form of the'contact means or clasp device adaptable for use inthe form of the invention shown forexample in FIGS. 3 to 8 of thedrawings.

This contact means or clasp would replace the element 21 and willprovide an improved functional interrelationship between the movablemeans and the contact means in that it will increase surface-to-surfacecontact between the inner surface of the contact means and the outersurface of the movable means in the adjusted position.

Thus, referring to FIGS. 15, 16 and 17 the contact means is designatedgenerally and consists of a relatively thin conductive strip ofmaterialsuch as has been described above for the contact means 21 and61. The strip is folded on itself to provide the convoluted shape shownin which two spaced and rounded end portions as at 91 and 92 providemeans to permit an upper member 93 to pivot relative a lower member 94suitably spaced therefrom when the movable means 96 is moved intooperative position with said contact means as is illustrated by thevarious phantomized positions of the movable member in FIG. 18 of thedrawings.

Thelower member 94 is connected to one of the end portions 92 and aconnecting member 97 connects to the end portion 92 remote from thelower member 94 at one end and at the other end to the end portion 91whichis continuous at its other end with the upper member 93 all ofwhich is clearly shown in FIGS. 15 and 16 of the drawings. 1

During operation of a variable trimmer capacitor which includes thisalternate form of contact member asthe movable member 96 enters intoengagement with the end portion 91 snug engagement will occur betweenthe respective coacting faces of the upper member 93. the lower member94 and the outer face of the movable member 96.

When the movable member 96 extends inwardly for engagement of therespective contacting surfaces of the upper member 93and the lowermember 94, the upper member 93 will initially pivot about the endportion 92. As the movable member 96 extends inwardly further andfurther in order to accommodate engagement, the force being exerted bythe movable member will be transmitted -to both the upper member 93 andthe connecting member 97 and the combination of the upper member 93, theend portion 91 and the con necting member 97 will then pivot about therespective end portions 91 and so as to maintain firm and operativeconnection with the outer surface of the movable member 96.

VARIABLE RESISTOR I justablemeans made to coact therewith can provide avariety of sub-miniature 'electricalcomponents. .This form of the ipresent invention are illustrated in FIGS. 19- to 24 and will now bedescribed.

Thus, referring to FIGS. 19 to 23 a variable resistor componentgenerally designated 100 is illustrated as including resistor means 101support means 102 and movable means 103.

The flat resistor means 101 may bev any suitable type of resistor. Thisis in electrical connectionwith one side of an electronic circuit whichis disposed on a substrate.

While a resistor 101 is shown it is thought clear that instead of asingle resistor that a plurality of spaced resistance elements or aplurality of switch contacts could also be used in place of the resistorelement 101 without departing from the scope of the present invention aswill be understood by those skilled in the art.

The adjustable meanswhich coacts with the resistor element 101- includesa support member or shuttle holder 102 which is made of the same type ofconductive materials above described for the forms of the inventionshown in FIGS. 2 and 9 of the drawings, and thus can be formed into aU-shaped member substantially similar in cross-section to the U-shape ofthe support members or shuttle holders shown in these forms of theinventions. It differs therefrom in that it includes additionalstructure to permit acantilevered or overhung arrangement for themovable means 103 with respect to the resistor pad or element 101. I

Thus the support member of shuttle holder 102 includes a rounded endportion as at 104 to which is connected an upper leg 105 and a lower leg106 so mounted that they are in stressed or compression relation to eachother to thus bring the central portions 107 of upper leg 105 and thefree end portion 108 of the lower leg 106 remote from the end portion104 closer to each other to form a wedge shaped space 109 all of whichis clearly shown in FIGS. 20 and 22 of the drawings.

The lower leg 106 provides means for affixing the support member 101 tothe conductive portion of the electrical circuit on the side thereofremote from the side of the circuit to which the resistor or impedanceelement 101 will be connected.

From the central portion 107 of the upper leg 105 there are a pair oflongitudinally extending arms 110 and 111 which form between them aguide groove or space as at 112. Additionally, the upper leg 105includes pairs of side guides in spaced relation to each other asindicated by elements 113, 114, 115 and 116. Elements 113 and 115 are inspaced relation to each other and are connected to one side of upper leg105 and guides 114 and 116 are in spaced relationship to each other andare connected to the opposite side of upper leg 105. These members willact to hold the movable member 103 from slipping sideways when themovable member 103 is mounted for operation on the support member orshuttle holder 101.

Additionally, elements 113 and 114 have front stops as at 117 and 118which coact with the movable means to limit the forward movementthereof.

The movable member or shuttle includes a slide portion 119 and a fingerportion generally designated 120. Finger portion 120 is in the form of aU-shaped element having an upper arm 121 and a lower arm 122 connectedrespectively to a rounded end portion 123 which forms a contact means asat 124 at the lowermost side thereof for contact with the resistor meansor impedance element 101 when the movable means 103 is moved foroperative engagement therewith.

The upper arm 121 of the finger member 120 is connected at the endremote from the rounded end portion 123 to the slide element 119 of themovable member 103. The lower arm 122 of the finger member 120 extendsalong the longitudinal line of the movable member 103 in spaced relationto the upper arm 121 and as indicated in FIGS. 19, 20 and 22 is slightlylonger than upper arm 121 so that it extends for a portion of its lengthunder the slide element 119 of the movable member 103.

At the end of the lower arm 122 remote from the rounded end portion 123a contact shoe 125 is formed.

It will be noted that the lower arm 122 ofthe finger member 120 isdisposed so that in assembled position the end adjacent the contactmeans 124,is maintained above the surface of the resistor means 101.Stated another way the lower leg 122 forms an acute angle with thehorizontal and slopes upwardly in assembled position from the contactshoe 125 to the contact means 124 so that the movable member is limitedto line contact with the resistor means or impedance element 101.

The slide element 119 of the movable member 103 is also shown with apair of spaced grooves 126 and 127 struck transversely in the side edgesof the slide element 119 and inwardly from a gripping or adjusting tab128 formed at the end of the slide element 119 remote from the endconnected to the finger member 120. The grooves 126 and 127 aresufficiently wide so that during assembly the slide element 119 andfinger member 120 may be sprung outwardly and slipped over the frontstops 117 and 118 until the slide element 119 is brought into engagementwith the upper surface of the upper leg 105 on the support member orshuttle 103.

When the movable member 103 is thus assembled the finger member 120 willbe disposed in the guide groove or space 112 between the arms 110 and111 formed on the support member 102. The lower arm 122 of the fingermember 120 will be held snugly between the upper leg 105 and thelower-leg 106 of the support member 102 so that the contact shoe 125will be in the wedge-shaped space 109. The compressive relationshipbetween the upper leg 105 and the lower leg 106 will force the contactshoe 125 into engagement with the inner surface of the support member102 as is clearly shown in FIGS. 20 and 22 of the drawings.

FIG. 21 further shows that the slide guides 113, 114, and 116 act toprevent sidewise movement of the movable member 103 and coact with theguide groove or space 112 to permit or maintain the movement of themovable member 103 substantially along the longitudinal line of theresistor means or impedance element 101.

It will be noted that the lower face of the upper leg 105 and thecontact shoe 125 stay in electrical connection in all adjusted positionsof the movable member 103 and that the movable member can move betweencertain limits either to non-engagement as where the end of the lowerarm 122 is in engagement with the inner surface of the rounded endportion 104 of the support member 102 or on outward movement forengagement with the resistor means or impedance element 101 until theadjusting tab 128 engages the front stops 117 and 1 l8;

CANTILEVERED VARIABLE TRIMMER CAPACITOR WITH CHIP TYPE IMPEDANCE MEANSFIG. 24 shows that the cantilevered or overhung form of adjusting meansis equally applicable for use as a Variable Trimmer type capacitor.

This is accomplished by replacing the resistor pad 101 with a chipelement as at 151 connected into the electronic circuit by any suitablemeans so as to provide a suitable impedance means having a ceramiccoating and modifying the finger element to eliminate the contact means124 and to widen the lower leg as shown at 152 to provide when broughtinto operative position with the chip the upper or other plate of thecapacitor.

The other parts will be identical with those above described for theform of the invention shown in FIGS. 19 to 23 and the operativerelations will be the same as that above described for the forms of theinvention shown in FIGS. 2 and 9 of the drawings.

Thus, as has been illustrated above, we have provided a simple variableelectronic component of great versatility and with minimum parts adaptedto be made in particular for very small size electronic circuits.

The variable electronic component is characterized by the fact that theelements are independently and directly connected to the circuit andhave no drive mechanism for operation.

The elements of the variable electronic component further are soconstructed that they have good electrical contact at all times andsubstantial misalign can occur without interferring with this electricalconnection between the elements. Thus, in contrast to many miniatureprior art devices the variable electronic components herein disclosedproduce limited or very little electrical noise; have low contactresistance and minimal electrical inductance in use and in assembledrelation in the circuit to which they are connected.

It is considered manifest that many variations to the structuresdescribed above in detail with respect to the disclosed embodiment canbe made without departing from the spirit and scope of this invention.

What is claimed is:

1. A variable electronic component for use in a sub-miniature electroniccircuit disposed on a supporting substrate comprising;

a. conductive contact means directly connectible to one side of theelectronic circuit and having a portion forming a planar surface,

. u-shaped, conductive support means directly connectible to the otherside of said electronic circuit independent of and in predeterminedspaced relation to said contact means,

c. movable means slidably mounted in said support means and adjusted formovement into and out of engagement with the planar surface of saidcontact means,

d. means on said support means to normally maintain positive engagementwith the movable means to hold the movable means in all given positionsof adjustment relative the contact means, and

e. means between the planar surface of said contact means and saidmovable means to provide a desired range of impedance characteristics tosaid variable electronic components on movement of the movable means.

2. In a variable electronic component as claimed in claim 1 wherein,

a. stop' means is formed on said support means to limit the adjustableoutward movement of the movable means on disengagement thereof from thecontact means,

b. and at least one other stop member disposed to coact with saidmovable means at full inward movement thereof during engagement with thecontact means.

3. In a variable electronic component as claimed in claim 1 including,

a. guide means on the support means,

b. said movable member operatively associated with the guide 'means toprevent relative sidewise movement of the movable member duringadjustment thereof.

4. In a variable electronic component as claimed in claim 1 wherein,

a. the contact means is U-shaped and is stressed to coact with thesupport means in holding said movable member in adjusted position.

b. said movable means to be forced into engagement with the U-shapedcontact means to move it into adjusted position.

5. In a variable electronic component as claimed in claim 1 wherein a.said contact means is substantially U-shaped having a bent portionandcontinuous therewith a pair of spaced leg means normally having thefree ends thereof in compression relationship to each other.

b. at least one of said leg means connected to the electronic circuitand forming a flat planar surface in assembled position,

0. the other of said leg means of the contact means having an upturnedengaging face to permit said movable means to be forced into engagementwith said U-shaped contact means,

d. and said U-shaped contact means to maintain at least one face of saidmovable means in snug engagement with the leg means forming the flatplanar surface.

6. In a variable electronic component as claimed in claim 3 wherein theU-shaped contact means is provided with guide means, and said movablemeans having a guide member disposed to engage the guide means.

7. In a variable electronic component as claimed in claim I wherein,

a. guide means are formed on said support means,

b. and said movable means is operatively associated with the c. saidmovable means substantially U-shaped in cross section and having a bentportion and continuous therewith a pair of spaced legs at least one ofwhich forms a flat planar surface disposed in assembled position to fitbetween legs of said support means and to engage the associate leg ofsaid support means having the flat planar surface,

d. and a contact shoe formed on the end of the leg of said movable meansdisposed between the legs of said support means to provide continuouselectrical contact therewith in all adjusted positions of the movablemember.

11. In a variable electronic component as claimed in claim 9 includingguide means on said support means, and said movable means disposed tocoact with the guide means to prevent sidewise movement of the movablemeans during adjustment guide means to prevent relative sidewisemovement of the movable member during adjustment thereof.

' 8. In a variable electronic component as claimed in claim 7 whereinthe guide means comprise spaced side members connected to opposite sidesof the support means, and the movable means has a width to just clearthe inner walls of the responsive side members.

9. In a variable electronic component as claimed in claim I wherein theimpedance means characteristic is established by a dielectric coating onthe inner surface of the contact means.

10. In a variable electronic component as claimed in claim I wherein,

a. the support means is substantially U-shaped having a bent portion andcontinuous therewith a pair of spaced legs normally having the free endsin compression relation to each other,

b. one of the legs of said U-shaped support means connected to theelectronic circuit and forming a flat planar surface,

thereof. I

12. In a variable electronic component as claimed in claim 11 whereinthe guide means include spaced side members connected normal to one ofthe legs of said U-shaped support means.

13. In a variable electronic component as claimed in claim 11 whereinthe guide means include a pair of spaced longitudinally extending armsconnected to one of the legs of said U- shaped support means, and afinger means on said movable member disposed to fit into and be guidedby the space between said pair of arms.

14. In a variable electronic component as claimed in claim 13 whereinthe impedance means characteristic is established by a dielectriccoating on the coacting surface of the contact means.

15. In a variable electronic component as claimed in Claim 13 whereinthe impedance means characteristic is established by a dielectriccoating on the coacting surface of at least one leg of the movablemeans.

16. In a variable electronic component as claimed in Claim 9 wherein,

a. stop means is formed on said support means to limit the adjustablemovement of the movable means out of engagement with the contact means,

b. and at least one other stop means is formed on the support means tocoact with said movable means to limit movement thereof into engagementwith the contact means.

17. In a variable electronic component as claimed in Claim 13 whereinthe finger means on the movable member is substantially U-shaped,

a. said finger means having a bent portion and an upper leg and a lowerleg continuous with the bent portions,

b. the lower leg having a contact part at the end adjacent the bentportion and a contact shoe at the end remote from the bent portion,

c. said contact part disposed to operatively engage the contact means,

d. and said contact shoe in continuous conductive connection with thesupport means.

l8. The combination with an electronic circuit on a support substrate ofa variable electronic component adaptable for use therein comprising:

a. at least one conductive contact means connected to one side of theelectronic circuit and mounted therewith to the substrate, said contactmeans having a portion forming a planar surface,

b. at least one u-shaped conductive support means connected to the otherside of the electronic circuit and mounted therewith to the substrateindependent of and in predetermined spaced relation to the contactmeans,

movable means electrically connected to and slidably mounted on saidsupport means for adjustable and operable engagement with the planarsurface of the contact means,

d. means on said support means to normally maintain positive engagementwith the movable means to hold the movable means in all given positionsof adjustment relative the contact means, and

e. means between the planar surface of said contact means 20. In avariable electronic component as claimed in claim and said movable meansto provide a desired range of im- 19 wherein,

pedance characteristics to said variable electronic component onmovement of the movable means. 19. In a variable electronic component asclaimed in claim 2 wherein,

a. the movable means 15 u-shaped and 18 mounted so as to inand he ushaped support means facing each other and termesh with the u-shapedsupport means,

. c. said movable means 15 forced mto engagement with the ub. and theu-shaped support means is stressed to provide the h d t t n I V6 in t td means for maintaining positive engagement of the mova- 10 s ape con acmea S mo n 0a Jus e posl ble means to hold the same in all adjustedpositions.

a. the contact means is u-shaped and is stressed to coact with thesupport means for holding said movable member in adjusted position.

b. the respective open ends of the u-shaped contact means

1. A variable electronic component for use in a sub-miniature electroniccircuit disposed on a supporting substrate comprising; a. conductivecontact means directly connectible to one side of the electronic circuitand having a portion forming a planar surface, b. u-shaped, conductivesupport means directly connectible to the other side of said electroniccircuit independent of and in predetermined spaced relation to saidcontact means, c. movable means slidably mounted in said support meansand adjusted for movement into and out of engagement with the planarsurface of said contact means, d. means on said support means tonormally maintain positive engagement with the movable means to hold themovable means in all given positions of adjustment relative the contactmeans, and e. means between the planar surface of said contact means andsaid movable means to provide a desired range of impedancecharacteristics to said variable electronic components on movement ofthe movable means.
 2. In a variable electronic component as claimed inclaim 1 wherein, a. stop means is formed on said support means to limitthe adjustable outward movement of the movable means on disengagementthereof from the contact means, b. and at least one other stop memberdisposed to coact with said movable means at full inward movementthereof during engagement with the contact means.
 3. In a variableelectronic component as claimed in claim 1 including, a. guide means onthe support means, b. said movable member operatively associated withthe guide means to prevent relative sidewise movement of the movablemember during adjustment thereof.
 4. In a variable electronic componentas claimed in claim 1 wherein, a. the contact means is U-shaped and isstressed to coact with the support means in holding said movable memberin adjusted position. b. said movable means to be forced into engagementwith the U-shaped contact means to move it into adjusted position.
 5. Ina variable electronic component as claimed in claim 1 wherein a. saidcontact means is substantially U-shaped having a bent portion andcontinuous therewith a pair of spaced leg means normally having the freeends thereof in compression relationship to each other. b. at least oneof said leg means connected to the electronic circuit and forming a flatplanar surface in assembled position, c. the other of said leg means ofthe contact means having an upturned engaging face to permit saidmovable means to be forced into engagement with said U-shaped contactmeans, d. and said U-shaped contact means to maintain at least one facEof said movable means in snug engagement with the leg means forming theflat planar surface.
 6. In a variable electronic component as claimed inclaim 3 wherein the U-shaped contact means is provided with guide means,and said movable means having a guide member disposed to engage theguide means.
 7. In a variable electronic component as claimed in claim 1wherein, a. guide means are formed on said support means, b. and saidmovable means is operatively associated with the guide means to preventrelative sidewise movement of the movable member during adjustmentthereof.
 8. In a variable electronic component as claimed in claim 7wherein the guide means comprise spaced side members connected toopposite sides of the support means, and the movable means has a widthto just clear the inner walls of the responsive side members.
 9. In avariable electronic component as claimed in claim 1 wherein theimpedance means characteristic is established by a dielectric coating onthe inner surface of the contact means.
 10. In a variable electroniccomponent as claimed in claim 1 wherein, a. the support means issubstantially U-shaped having a bent portion and continuous therewith apair of spaced legs normally having the free ends in compressionrelation to each other, b. one of the legs of said U-shaped supportmeans connected to the electronic circuit and forming a flat planarsurface, c. said movable means substantially U-shaped in cross sectionand having a bent portion and continuous therewith a pair of spaced legsat least one of which forms a flat planar surface disposed in assembledposition to fit between legs of said support means and to engage theassociate leg of said support means having the flat planar surface, d.and a contact shoe formed on the end of the leg of said movable meansdisposed between the legs of said support means to provide continuouselectrical contact therewith in all adjusted positions of the movablemember.
 11. In a variable electronic component as claimed in claim 9including guide means on said support means, and said movable meansdisposed to coact with the guide means to prevent sidewise movement ofthe movable means during adjustment thereof.
 12. In a variableelectronic component as claimed in claim 11 wherein the guide meansinclude spaced side members connected normal to one of the legs of saidU-shaped support means.
 13. In a variable electronic component asclaimed in claim 11 wherein the guide means include a pair of spacedlongitudinally extending arms connected to one of the legs of saidU-shaped support means, and a finger means on said movable memberdisposed to fit into and be guided by the space between said pair ofarms.
 14. In a variable electronic component as claimed in claim 13wherein the impedance means characteristic is established by adielectric coating on the coacting surface of the contact means.
 15. Ina variable electronic component as claimed in Claim 13 wherein theimpedance means characteristic is established by a dielectric coating onthe coacting surface of at least one leg of the movable means.
 16. In avariable electronic component as claimed in Claim 9 wherein, a. stopmeans is formed on said support means to limit the adjustable movementof the movable means out of engagement with the contact means, b. and atleast one other stop means is formed on the support means to coact withsaid movable means to limit movement thereof into engagement with thecontact means.
 17. In a variable electronic component as claimed inClaim 13 wherein the finger means on the movable member is substantiallyU-shaped, a. said finger means having a bent portion and an upper legand a lower leg continuous with the bent portions, b. the lower leghaving a contact part at the end adjacent the bent portion and a contactshoe at the end remote from the bent portion, c. said contact partdisposed to operatively engage the contact means, d. and said contactshoe in continuous conductive connection with the support means.
 18. Thecombination with an electronic circuit on a support substrate of avariable electronic component adaptable for use therein comprising: a.at least one conductive contact means connected to one side of theelectronic circuit and mounted therewith to the substrate, said contactmeans having a portion forming a planar surface, b. at least oneu-shaped conductive support means connected to the other side of theelectronic circuit and mounted therewith to the substrate independent ofand in predetermined spaced relation to the contact means, c. movablemeans electrically connected to and slidably mounted on said supportmeans for adjustable and operable engagement with the planar surface ofthe contact means, d. means on said support means to normally maintainpositive engagement with the movable means to hold the movable means inall given positions of adjustment relative the contact means, and e.means between the planar surface of said contact means and said movablemeans to provide a desired range of impedance characteristics to saidvariable electronic component on movement of the movable means.
 19. In avariable electronic component as claimed in claim 2 wherein, a. themovable means is u-shaped and is mounted so as to intermesh with theu-shaped support means, b. and the u-shaped support means is stressed toprovide the means for maintaining positive engagement of the movablemeans to hold the same in all adjusted positions.
 20. In a variableelectronic component as claimed in claim 19 wherein, a. the contactmeans is u-shaped and is stressed to coact with the support means forholding said movable member in adjusted position, b. the respective openends of the u-shaped contact means and the u-shaped support means facingeach other, and c. said movable means is forced into engagement with theu-shaped contact means to move it into adjusted position.